JavaScript: Be more lenient about keywords used as identifiers.

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -2106,8 +2106,10 @@ public class Parser {
 			if (this.inAsync && this.value.equals("await"))
 				this.raiseRecoverable(this.start, "Can not use 'await' as identifier inside an async function");
 			name = String.valueOf(this.value);
-		} else if (liberal && this.type.keyword != null) {
+		} else if (this.type.keyword != null) {
 			name = this.type.keyword;
+			if (!liberal)
+				raiseRecoverable(this.start, "Cannot use keyword '" + name + "' as an identifier.");
 		} else {
 			this.unexpected();
 		}
@@ -2264,9 +2266,6 @@ public class Parser {
 		if (this.options.ecmaVersion() < 6)
 			return this.parseIdent(false);
 
-		if (this.type == TokenType.name)
-			return this.parseIdent(false);
-
 		if (this.type == TokenType.bracketL) {
 			Position start = this.startLoc;
 			this.next();
@@ -2278,8 +2277,7 @@ public class Parser {
 		if (this.type == TokenType.braceL)
 			return this.parseObj(true, null);
 
-		this.unexpected();
-		return null;
+		return this.parseIdent(false);
 	}
 
 	protected List<Expression> parseBindingList(TokenType close, boolean allowEmpty, boolean allowTrailingComma, boolean allowNonIdent) {

javascript/extractor/tests/errors/input/kwident.js

@@ -0,0 +1 @@
+var class = 23;

javascript/extractor/tests/errors/output/trap/kwident.js.trap

@@ -0,0 +1,104 @@
+#10000=@"/kwident.js;sourcefile"
+files(#10000,"/kwident.js","kwident","js",0)
+#10001=@"/;folder"
+folders(#10001,"/","")
+containerparent(#10001,#10000)
+#10002=@"loc,{#10000},0,0,0,0"
+locations_default(#10002,#10000,0,0,0,0)
+hasLocation(#10000,#10002)
+#20000=@"global_scope"
+scopes(#20000,0)
+#20001=@"script;{#10000},1,1"
+#20002=*
+lines(#20002,#20001,"var class = 23;","
+")
+#20003=@"loc,{#10000},1,1,1,15"
+locations_default(#20003,#10000,1,1,1,15)
+hasLocation(#20002,#20003)
+numlines(#20001,1,1,0)
+#20004=*
+tokeninfo(#20004,7,#20001,0,"var")
+#20005=@"loc,{#10000},1,1,1,3"
+locations_default(#20005,#10000,1,1,1,3)
+hasLocation(#20004,#20005)
+#20006=*
+tokeninfo(#20006,7,#20001,1,"class")
+#20007=@"loc,{#10000},1,5,1,9"
+locations_default(#20007,#10000,1,5,1,9)
+hasLocation(#20006,#20007)
+#20008=*
+tokeninfo(#20008,8,#20001,2,"=")
+#20009=@"loc,{#10000},1,11,1,11"
+locations_default(#20009,#10000,1,11,1,11)
+hasLocation(#20008,#20009)
+#20010=*
+tokeninfo(#20010,3,#20001,3,"23")
+#20011=@"loc,{#10000},1,13,1,14"
+locations_default(#20011,#10000,1,13,1,14)
+hasLocation(#20010,#20011)
+#20012=*
+tokeninfo(#20012,8,#20001,4,";")
+#20013=@"loc,{#10000},1,15,1,15"
+locations_default(#20013,#10000,1,15,1,15)
+hasLocation(#20012,#20013)
+#20014=*
+tokeninfo(#20014,0,#20001,5,"")
+#20015=@"loc,{#10000},2,1,2,0"
+locations_default(#20015,#10000,2,1,2,0)
+hasLocation(#20014,#20015)
+toplevels(#20001,0)
+#20016=@"loc,{#10000},1,1,2,0"
+locations_default(#20016,#10000,1,1,2,0)
+hasLocation(#20001,#20016)
+#20017=@"var;{class};{#20000}"
+variables(#20017,"class",#20000)
+#20018=*
+stmts(#20018,18,#20001,0,"var class = 23;")
+hasLocation(#20018,#20003)
+stmtContainers(#20018,#20001)
+#20019=*
+exprs(#20019,64,#20018,0,"class = 23")
+#20020=@"loc,{#10000},1,5,1,14"
+locations_default(#20020,#10000,1,5,1,14)
+hasLocation(#20019,#20020)
+enclosingStmt(#20019,#20018)
+exprContainers(#20019,#20001)
+#20021=*
+exprs(#20021,78,#20019,0,"class")
+hasLocation(#20021,#20007)
+enclosingStmt(#20021,#20018)
+exprContainers(#20021,#20001)
+literals("class","class",#20021)
+decl(#20021,#20017)
+#20022=*
+exprs(#20022,3,#20019,1,"23")
+hasLocation(#20022,#20011)
+enclosingStmt(#20022,#20018)
+exprContainers(#20022,#20001)
+literals("23","23",#20022)
+#20023=*
+entry_cfg_node(#20023,#20001)
+#20024=@"loc,{#10000},1,1,1,0"
+locations_default(#20024,#10000,1,1,1,0)
+hasLocation(#20023,#20024)
+#20025=*
+exit_cfg_node(#20025,#20001)
+hasLocation(#20025,#20015)
+successor(#20018,#20021)
+successor(#20022,#20019)
+successor(#20021,#20022)
+successor(#20019,#20025)
+successor(#20023,#20018)
+#20026=*
+jsParseErrors(#20026,#20001,"Error: Cannot use keyword 'class' as an identifier.","var class = 23;
+")
+#20027=@"loc,{#10000},1,5,1,5"
+locations_default(#20027,#10000,1,5,1,5)
+hasLocation(#20026,#20027)
+#20028=*
+lines(#20028,#20001,"var class = 23;","
+")
+hasLocation(#20028,#20003)
+numlines(#20001,1,0,0)
+numlines(#10000,1,1,0)
+filetype(#10000,"javascript")